The present invention relates to an electroluminescent lamp, and more particularly to an electroluminescent lamp having a level electrical connection structure for receipt of power.
A conventional electroluminescent lamp will be described with reference to FIG. 1. A transparent electrode 2 is provided which extends over a top surface of a transparent substrate 1. An electroluminescent layer 3 is selectively provided on a predetermined first area of a top surface of the transparent electrode 2. A reflective insulation film 4 is provided which extends over a top surface of the electroluminescent layer 3. A first-side conductive layer 5 extends over a top surface of the reflective insulation film 4 except on a region adjacent to a boundary between the above first area and a second area opposite to the above first area. A second-side conductive layer 6 extends on the second area of the top surface of the transparent electrode 2 provided that the second-side conductive layer 6 is spaced via a small gap from the electroluminescent layer 3. The second-side conductive layer 6 is in contact with the transparent electrode 2 so that the second-side conductive layer 6 is electrically connected to the transparent electrode 2.
In use of the above electroluminescent lamp, a connector is attached on the above electroluminescent lamp, wherein the connector has pins which securely contact with the first-side and second-side conductive layers 5 and 6. Normally, such connector is a pressing type connector such as a rubber connector, pin connector or spring connector. As illustrated in FIG. 1, the first-side and second-side conductive layers 5 and 6 differ in level from each other. This causes a difference in contact pressure to the connector pins between the first-side and second-side conductive layers 5 and 6. This may cause a non-uniform electrical contact of the first-side and second-side conductive layers 5 and 6 to the connector pins. Such a non-uniform electrical contact may further cause an electrical disconnection or unstable electrical connection of the first-side and second-side conductive layers 5 and 6 to the connector pins. This makes it difficult to be certain that the above electroluminescent lamp will remain ON.
Another electroluminescent lamp will subsequently be described with reference to FIG. 2. A transparent electrode 2 is provided which extends over a top surface of a transparent substrate 1. An electroluminescent layer 3 is selectively provided on a predetermined first area of a top surface of the transparent electrode 2. A reflective insulation film 4 extends over a top surface of the electroluminescent layer 3. A first-side conductive layer 5 extends over a top surface of the reflective insulation film 4 except on a side region adjacent to a boundary between the above first area and a second area opposite to the above first area. An insulation layer 8 extends on the above side region of the reflective insulation film 4 and the first-side conductive layer 5 but only on a region relatively near the above side region of the reflective insulation film 4. A second-side conductive layer 6 extends on the second area of the top surface of the transparent electrode 2 and over the insulation layer 8 so that the second-side conductive layer 6 is isolated by the insulation layer 8 from the first-side conductive layer 5.
In use of the above electroluminescent lamp, a connector is attached on the above electroluminescent lamp, wherein the connector has pins which securely contact with the first-side and second-side conductive layers 5 and 6. Normally, such a connector is a pressing type connector such as a rubber connector, pin connector or spring connector. As well illustrated in FIG. 2, however, the first-side and second-side conductive layers 5 and 6 differ in level from each other. This causes a difference in contact pressure to the connector pins between the first-side and second-side conductive layers 5 and 6. This may cause a non-uniform electrical contact of the first-side and second-side conductive layers 5 and 6 to the connector pins. Such a non-uniform electrical contact may further cause an electrical disconnection or unstable electrical connection of the first-side and second-side conductive layers 5 and 6 from the connector pins. This makes it difficult to be certain that the above electroluminescent lamp will remain ON.
Furthermore, as described above and illustrated in FIG. 2, the second-side conductive layer 6 is provided on the insulation layer 8 whilst the first-side conductive layer 5 is provided on the reflective insulation film 4. The insulation layer 8 serves as a base layer for the second-side conductive layer 6 whilst the reflective insulation film 4 serves as a base layer for the first-side conductive layer 5. The insulation layer 8 and the reflective insulation film 4 largely differ from each other in material, structure, strength and elasticity, for which reason when the connector pins are pressing the first-side and second-side conductive layers 5 and 6, the insulation layer 8 and the reflective insulation film 4 are deformed. Those deformations of the insulation layer 8 and the reflective insulation film 4 may cause non-uniform contact pressure of the contact pins on the first-side and second-side conductive layers 5 and 6. This may cause a non-uniform electrical contact of the first-side and second-side conductive layers 5 and 6 to the connector pins. Such a non-uniform electrical contact may further cause an electrical disconnection or unstable electrical connection of the first-side and second-side conductive layers 5 and 6 from the connector pins. This makes it difficult to be certain that the above electroluminescent lamp will remain ON.
In the above circumstances, it had been required to develop a novel electroluminescent lamp which has substantially no difference in contact pressure between the connector pins and the first-side and second-side conductive layers provided in the electroluminescent lamp.